Cyclic sulfur-chlorinated oil and process of making

ABSTRACT

1. A PROCESS WHICH COMPRISES REACTING A NORMALLY LIQUID SULFUR HALIDE WITH AN OIL OBTAINED FROM THE CRACKING OF PETROLEUM SAID OIL, CONTAINING AS A MAJOR INGREDIENT POLYNUCLEAR AROMATICS AND BOILING BETWEEN 350 AND 800* F. AND HAVING SEPARATED THEREFROM BY SULFURIC ACID TREATMENT THE MAJORITY OF IMPURITIES WHICH FORM A PERMANENT SLUDGE WHEN REACTED WITH A NORMALLY LIQUID SULFUR HALIDE, AND SEPARATING ANY RESULTING PRECIPITATE AND HYDROGEN HALIDE FORMED THEREFROM TO LEAVE A STABLE AND HOMOGENEOUS CYCLIC OIL HAVING ANTI-WELD PROPERTIES, CHARACTERIZED BY LACK OF OFFENSIVE ODOR AND CONTAINING UP TO ABOUT 20% TOTAL SULFUR AND UP TO ABOUT 5% TOTAL CHLORINE.

United States Patent 3,847,827 CYCLIC SULFUR-CHLORINATED OIL AND PROCESSOF MAKING Robert L. Dinsmore, Long Beach, and Herbert D. Ivey, Pasadena,Calif., assignors to Lubrication Company of America, Los Angeles, Calif.No Drawing. Filed Sept. 10, 1973, Ser. No. 395,741 Int. Cl. C10m N38 US.Cl. 25248.8 11 Claims ABSTRACT OF THE DISCLOSURE A sulfur-chlorinatedcyclic oil having anti-weld properties, and being useful as a cutting orlubricating oil is produced from an oil having a substantial amount ofpolynuclear aromatics and which is generally a waste product of acatalytic cracking refinery process. The sulfur-chlorinated cyclic oilis formed by reacting the oil with about 0.1% w. to about 10% w. ofsulfuric acid, the amount of sulfuric acid being less than the maximumamount required to react completely with the oil. After removing thesludge formed by this reaction, the oil is reacted with a normallyliquid, sulfur halide, after which any resulting precipitate and gaseoushalides are separated to leave a stable and homogeneous oil whichpossesses anti-weld and extreme pressure properties when used alone orupon dilution as a cutting or lubricating oil, and which contains up toabout 20% W. of total sulfur and up to about w. of total chlorine.

BACKGROUND OF THE INVENTION This invention generally relates to cuttingand lubricating oils, and more particularly to a process of makingsulfur-chlorinated cyclic oils having anti-weld properties. With theincreasingly short supply of crude oil, it has become more important tofully utilize all of the products of a crude oil refining process. Onemajor by-product of an oil refining process are polynuclear compoundswhich usually contain a variety of side chains. During the oil refinerycracking process, polynuclear compounds may be formed from thecyclization of parafiins, dehydrogenation of aromatics or by a varietyof other reactions. These by-products, which are commonly called cyclicoils, exhibit little lubricating properties and are often discarded ormarketed as weed killers, etc.

With the increased scarcity of raw crude oil causing increased pricesfor oil products, the use of inexpensive cyclic oils as a startingmaterial for the manufacture of a cutting oil or cutting oil additivewith anti-weld and extreme pressure properties is very desirable.Cutting oils used in the machining of steel and like metals requireanti-weld properties to prevent the binding up of the machining metalwith the work piece. An antiweld lubricant is especially required forthe making of deep cuts in soft metal where the Work piece may approachits welding temperature. Ideally, a lubricating oil having anti-weldproperties reacts with the tool and work surface just below the weldtemperature to pre vent the two from welding together. Such anti-weldlubricating oils are usually made up of sulfur compounds which form aniron sulfide with the tool and work surface below the weld temperatureto prevent these surfaces from welding together.

The effectiveness of a sulfur-containing anti-weld lubricating oil isoften dependent upon the amount of sulfur which is available to reactjust below the weld tem perature. Generally, sulfurized fats, esters andwaxes have tightly-bound sulfur atoms which will not readily react belowthe weld temperature unless also exposed to extreme pressure.Consequently, such materials as sulfur-chlorinated fats and esters findtheir use as extreme pressure additives rather than anti-weld additivesin lubricating oils. These materials release little if any sulfur orchlorine below the weld temperature of soft metals. They possess,however, cooling and loadbearing properties to prevent the welding ofhard metals at extreme pressures.

On the other hand, incorporation of loosely bound sulfur or halogenatoms into a cutting oil, so that the atoms are active at roomtemperature may result in corrosion of work pieces and tools. Also, freesulfur may result in instability of the oil itself. Thus, the idealsulfurized cutting oil is one which is inactive under ambientconditions, but which exhibits anti-weld properties at a temperaturebelow the welding temperature of the work piece, and extreme pressureproperties for the machining of harder metals.

'In US. Pat. 3,309,315 assigned to the same assignee as the presentinvention, it was discovered that by selection of a mildly orincompletely acid treated naphthenic mineral oil, a concentration ofsulfur useful to impart anti-weld properties could be introduced intothe oil by reaction with a sulfur halide. However, it was heretoforbelieved that the cyclic oil refining by-products such as the productsof a catalytic cracking process were such that further treatment wouldresult in such sludge formation that the manufacture of a useful productwould be uneconomical.

Although the reaction of a sulfur halide, such as sulfur monochloride,with substantially pure cyclic compounds such as naphthalene andanthracene derivatives are known, (U.S. Pat. 2,402,685) it was neverthought that the sulfur-chlorination of the sludge forming cyclicby-products of a crude oil refinery process would yield a usefulproduct. Generally, such a by-product contains a large amount ofimpurities including nitrogen, sulfur, and unsaturated olefiniccompounds as well as long sidechains, which inhibit any reaction. Itwould appear uneconomical if not impossble to economically react thesecompounds further to form a useful product.

SUMMARY OF THE INVENTION A cracked oil, which is generally a by-productof an oil refining process and which contains substantial amounts ofpolynuclear aromatic compounds having a viscosity index below 0 andboiling between 350 and 800 F., is reacted with about 0.1% w. to about10% w. of sulfuric acid, such amount of sulfuric acid being less thanthe maximum amount required to react completely with the oil but whichwill precipitate unwanted impurities. After sulfuric acid treatment, theoil may optionally be neutralized by treatment with a base, or adsorbantclay may be used to adsorb soluble acids. Preferably, however, the acidtreated oil is not neutralized, but rather, directly reacted with anormally liquid sulfur halide which, after the resulting sludge andhydrogen halide are removed, forms a stable and homogeneous oil havinganti-weld and extreme pressure properties, characterized by lack ofolfensive odor, a clear, darkreddish color, and containing up to about20% total sulfur and up to about 5% total chlorine.

PREFERRED EMBODIMENT One of the major by-products of a crude oilrefining process is cyclic oils generally containing one to four ringedaromatic compounds, such compounds generally having substantiallysaturated side chains of less than ten carbon atoms. Such a by-productmay also contain naphthenes, other saturated cyclic compounds, as wellas olefins and saturated aliphatic compounds. These by-products, whichhave undergone cracking in the oil refining process are generally oflittle commercial use, since they will readily form a sludge upon anyfurther reaction. Because of the large number of impurities contained inthese byproducts, much of which will quickly react to form a sludge, itis generally unfeasible to further treat them to make a useful product.

By separating out the fraction of such cyclic compounds, boiling withina range of 3.50 to 800 F. and preferably between 400 and 700 F., a lightcyclic oil, containing as a major ingredient two and three memberedringed compounds and generally having a viscosity index below isobtained.

This light cyclic oil having the polynuclear aromatics is then reactedwith up to about w. of sulfuric acid, such amount of acid beingsufficient to separate out unwanted impurities which will form a sludgeupon treatment with sulfur monochloride. Such impurities as nitrogen,oxygen and sulfur compounds are precipitated, yet the polynucleararomatics are left unreacted. Additionally, soluble sulfonic acidderivatives, commonly called red acids, are formed by the sulfuric acidtreatment. The insoluble reaction products (green acids) are firstremoved, after which optionally, the soluble red acids may beneutralized or removed. We have found that neutralization of these redacids is preferably not required for the sulfurmonochloride reaction.

After the sulfuric acid treatment, and the optional neutralization step,the oil is treated with a liquid sulfur halide, such as S Cl so as toproduce a useful anti-weld cutting oil. Up to about 32% w. S Cl may bereacted with the acid treated cyclic oil. However, addition of S Cl mustbe done in stages, since the initial reaction is rapid. We have foundthat the reaction generally requires no catalyst, especially if thecyclic oil is in the unneutralized state. It is believed that theunneutralized soluble sulfonic acids serve as a catalyst for the S Clreaction and may aid in retaining more C1 in the final product.

Although the reaction is not fully understood, it is believed that the SCl when reacted in the presence of sulfonic acids at preferably ambienttemperatures, forms a sulfur chlorinated oil of the general formula RSCland R-SS--Cl where R contains two and three ringed aromatic compounds.This is very different from other sulfur-chlorinated products such asfats or waxes which release sulfur or chlorine only under extremepressure. The extreme pressure is necessary for these products since thesulfur and chlorine are tightly bound to the carbon backbone by, forexample, the saturation of double bonds. However, since the cycliccompound of this invention also may contain substantial amounts ofunsaturated compounds which will undergo sulfur-chlorination to givetightly bound sulfur and chlorine atoms, the product of the presentinvention may be used as both an anti-weld and extreme pressureadditive.

Upon the addition of S Cl a substantial increase in viscosity anddarkening of color is apparent. In fact, at the completion of the S 01reaction, the oil is so dark, so viscous and so full of sludge as toappear unsuitable for any application. However, by blowing air at about150 F. through this product for a suflicient time to remove all gaseoushalides, evidenced by the lack of offensive odor, and then by removingany precipitate, a lubricating oil having a clear, reddish color with aviscosity of ranging from 90 to 200 SSU at 100 F. and useful as acutting oil by itself or upon dilution is obtained.

The invention will be better understood by reference to the specificexamples, which are illustrative of the invention, but not intended tobe limited thereto. Specifically, although in the specific examplessulfuric acid is used to remove and react with compounds which formsludge upon exposure to S Cl other means to remove such impurities maybe utilized without departing from the spirit and scope of theinvention.

4 EXAMPLE I Mobil MZY 409 cyclic oil from the Mobil Oil Co., having adistillation range between 400 and 700 F. is agitated with 4% w.concentrated sulfuric acid for minutes, allowed to settle for fourhours, after which the precipitate is separated.

EXAMPLE H The product of Example I, or a commercially available acidtreated cyclic oil such as Mobil MZY 413 from the Mobil Oil Co. isfurther treated with S CI To 860 gms. of unneutralized MZY 413 cyclicsour oil is added 82 gms. (9.5%) of S2012 at ambient temperatures withmixing by air blowing. The reaction is carried out in an iron kettlewhich may serve to catalyze the reaction.

Additional S Cl is added in intervals so as not to cause a rise intemperature of greater than 'F. After allowing the first S Cl to reactfor one half hour, 60 gms. (7%) of S Cl was added, and allowed to reactfor 15 minutes before a final addition of 73 gms. (8.5%) of S Cl wasmade. Air blowing was continued for an hour and the reaction vessel wasallowed to stand overnight. The reaction product at this point wasviscous, exceedingly dark and full of sludge so as to appear unsuitablefor any lubricating oil application. Air was then blown through the oilfor about 16 hours at 170 F. until no chlorine odor was present. Thisair blowing step resulted in the dissolution of much of the sludge,after which the remaining sludge was removed. The resulting product hadthe following properties:

Gravity API, 60 F 5.0.

Specific gravity, 60 F. 1.0366. Pounds per gallon 8.36. Viscosity SSU at100 F. 150.

Pour point Less than 0' F. Flash COC 245.

Total sulfur (ASTM D129) 11.5.

Total chlorine (D808) 2.01.

Copper corrosion at 72 F Minor.

Although the sulfur activity of this product at room temperature asindicated by the copper corrosion test does not appear to indicateanti-weld properties, the oil has demonstrated excellent anti-weldproperties in the field. It may be blended with pale oils, or may beused by itself if the proper lubricating fraction is selected. {it hasalso demonstrated extreme pressure properties in the cutting of hardmetals such as stainless steel or titanium.

As a cutting oil, 25% w. of the oil of Example I was blended with 75%pale mineral oil. When used in threading stainless steel pipe, nogouging was evidenced. Applications for the oil of this invention whichpossesses both anti-weld and extreme pressure properties include use asa cutting oil, alone or as an additive, for broaching, drilling andmachining operations as well as for use as a gear oil.

What is claimed is:

1. A process which comprises reacting a normally liquid sulfur halidewith an oil obtained from the cracking of petroleum said oil, containingas a major ingredient polynuclear aromatics and boiling between 350 and800 F. and having separated therefrom by sulfuric acid treatment themajority of impurities which form a permanent sludge when reacted with anormally liquid sulfur halide, and separating any resulting precipitateand hydrogen halide formed therefrom to leave a stable and homogeneouscyclic oil having anti-weld properties, characterized by lack ofoffensive odor and containing up to about 20% total sulfur and up toabout 5% total chlorine.

2. The process which comprises reacting an oil obtained from thecracking of petroleum and containing as a major ingredient polynucleararomatics having a viscosity index below 0 and boiling between 350 and800 F. with about 0.1% w. to about 10% w. of sulfuric acid, such amountof sulfuric acid being sufficient to remove the majority of impuritiesWhich form a permanent sludge when reacted with a normally liquid sulfurhalide but less than the amount required to react completely with theoil, removing the sludge formed thereby, reacting it with a normallyliquid sulfur halide and separating the resulting precipitate andhydrogen halide formed therefrom to leave a stable and homogeneous oilhaving anti-weld properties, characterized by lack of offensive odor andcontaining up to about 20% total sulfur and up to about 5% totalchlorine.

3. The process of claim 2 wherein the starting oil boils betwen 400 and700 F.

4. The process of claim 2 wherein said sulfur halide is substantiallysulfur monochloride.

5. The process of claim 4 wherein the sulfuric acid is about 0.5% w. toabout 5% w. and said sulfur monochloride is added in fractional amountsup to about 32% w. during an extended period of time up to about hours,at substantially ambient temperatures, the reaction proceeding until noodor of sulfur halide or hydrogen halide is evident upon heating toabout 200 F.

6. The process of claim 5 wherein the reaction proceeds for about 48hours.

7. The process which comprises reacting an oil obtained from thecracking of petroleum, said oil containing as its major ingredientcyclic compounds having more than one ring member boiling betwen 350 and800 F. and having a viscosity index of less than 0 with about 0.1% w. toabout 10% W. of sulfuric acid, such amount of sulfuric acid beingsufiicient to remove the majority of impurities which form a permanentsludge when reacted with a normally liquid sulfur halide but less thanthe amount required to react completely with the oil, removing thesludge formed thereby, reacting it with a normally liquid sulfur halideand separating the resulting precipitate and hydrogen halide formedtherefrom to leave a stable and homogeneous oil having anti-weldproperties and characterized by lack of offensive odor and containing upto about total sulfur and up to about 5% total chlorine in oil solubleorganic compounds which may be used as cutting oil by itself or upondilution.

8. The process of claim 7 wherein the starting oil boils between 400 and700 F.

9. The process of claim 7 wherein the final oil has a viscosity between90 and 220 SSU.

10. A cutting fluid containing homogeneously and stably dispersedtherein an anti-Weld quantity of the reaction product between a normallyliquid sulfur halide and a cyclic mineral oil, said reaction productbeing formed by reacting an oil obtained from a petroleum crackingprocess boiling between 350 and 800 F. having a viscosity index below 0and containing a major ingredient cyclic compound having more than onering member with about 0.1% w. to about 10% W. of sulfuric acid, suchamount of sulfuric acid being suflicient to remove the majority ofimpurities which form a permanent sludge when reacted with a normallyliquid sulfur halide but less than the maximum amount required to reactcom-. pletely with the oil, removing the sludge formed thereby, reactingit with a normally liquid, sulfur halide and separating the resultingprecipitate and hydrogen halide formed therefrom to leave a stable andhomogeneous oil having anti-weld and extreme pressure properties andcharacterized by lack of offensive odor and containing up to about 20%total sulfur and up to about 5% total chlorine.

11. The cutting fluid of claim 10 wherein the sulfur halide isessentially sulfur monochloride.

References Cited UNITED STATES PATENTS 3,309,315 3/1967 Hanna et a1 25242.4 2,112,677 3/1938 Muscat 252- 2,402,685 6/1946 Signaigo 260139 X2,628,228 2/1953 King et al. 252-139 X 2,859,172 11/1958 Reymond 208-96XFOREIGN PATENTS 507,385 6/1939 Great Britain 252-45 WARREN H. CANNON,Primary Examiner US. Cl. X.R. 25245; 260139

1. A PROCESS WHICH COMPRISES REACTING A NORMALLY LIQUID SULFUR HALIDEWITH AN OIL OBTAINED FROM THE CRACKING OF PETROLEUM SAID OIL, CONTAININGAS A MAJOR INGREDIENT POLYNUCLEAR AROMATICS AND BOILING BETWEEN 350 AND800* F. AND HAVING SEPARATED THEREFROM BY SULFURIC ACID TREATMENT THEMAJORITY OF IMPURITIES WHICH FORM A PERMANENT SLUDGE WHEN REACTED WITH ANORMALLY LIQUID SULFUR HALIDE, AND SEPARATING ANY RESULTING PRECIPITATEAND HYDROGEN HALIDE FORMED THEREFROM TO LEAVE A STABLE AND HOMOGENEOUSCYCLIC OIL HAVING ANTI-WELD PROPERTIES, CHARACTERIZED BY LACK OFOFFENSIVE ODOR AND CONTAINING UP TO ABOUT 20% TOTAL SULFUR AND UP TOABOUT 5% TOTAL CHLORINE.